The Intergovernmental Panel on Climate Change has repeatedly and falsely claimed that it depends entirely on peer-reviewed papers. Donna Laframboise used volunteers to check this claim and found that a significant part of the references in the fourth assessment report of the IPCC were to ‘grey literature’ – that is, press releases, ‘reports’ from pressure groups and the like, which are not remotely the normal peer reviewed scientific literature.

Yet even if all the citations used by the IPCC were peer-reviewed, this would not mean they were infallible. Peer review is not, never was, and never can be a general protection against prejudice, error, or misconception about scientific matters. That it seems otherwise to some people is a misapprehension on their part, reflecting widespread myths about the reality of human investigations into the natural world.

It is startling for non-scientists who actually visit the sausage factory of science for the first time. There, peer review proves to be an often biased, prejudicial, and perfunctory process contrary in every respect to popular expectations about science. But scientists know that no increased regulation or standards can ever improve things, because there are no higher authorities to appeal to in a domain of human endeavour where no one knows or ever knew the answers – hence the name ‘peer review’ and not ‘expert correction’.

Donna Laframboise observes that, ‘There is a reason publishing insiders are among peer review’s most derisive critics. They know it’s mostly just a game. Everyone is pretending that all is well despite a mountain of evidence to the contrary.’ Most scientists grudgingly tolerate peer review because they cannot think of anything better. Experienced ones do not expect much from it, even if they must play along to succeed given modern customs (until about the mid-20th century it hardly existed).

Most scientists cringe when they hear other scientists claim that because their work is peer-reviewed, they do not have to respond to criticisms, even those from qualified colleagues, whether peer-reviewed or not. Some surely do make such claims: ‘…many academics insist that the research they present to the world has been fully vetted. Indeed, they often behave as though it meets a standard unrivalled elsewhere’, observes Laframboise.

Furthermore, those same scientists retreat to the truth about the state of human knowledge of Nature when facts go against their claims. She points out that: ‘On the other hand, they take no responsibility when information they’ve produced turns out to be mistaken. In such cases everyone is then reminded that scholarly publishing is vii really just an exchange of ideas.’ Few competent scientists regard current scientific thinking as anything more than provisional. It is always fully open to challenge.

Peer-review is also abused as a form of gatekeeping to defend orthodox ideas from challenge, as Laframboise says: ‘Alternative schools of thought are more likely to encounter scorn than a fair hearing, and the secretive nature of peer review provides ample cover for intolerance and tribalism. . .It places unconventional thinkers at the mercy of their more conventional colleagues. Indeed, this approach seems designed to extinguish – rather than nurture – the bold, original thinking that leads to scientific breakthroughs.’ Many unorthodox ideas prove to be wrong, but they are the lifeblood of scientific advance. They challenge our orthodoxies, either sharpening them or overthrowing them. Thus the notion of challenging the orthodox is accepted in science by necessity, even if grudgingly.

Gatekeeping against the unorthodox is not remotely a new problem. Oracular mediocrities down the centuries have doggedly resisted human advances in knowledge from Galileo to Semmelweis to Einstein, and thousands of other cases that only the most learned science historians will ever know. Spectacular scandals come and go, but science is in the end a long game of the generations, not something played out in news cycles. So why then has the public debate about the perfunctory, crony, gate-keeping aspects of peer review grown in volume in the media now? Partly it is because science has become a ‘bigger’ and more centralized endeavor, with massive budgets invested in conventional wisdom, and more politicians involved in pushing certain conclusions. How else can one comprehend the term ‘orchestrated’ used by one founder of the IPCC to describe how scientific opinion was designed to be treated for the use of policymakers?

It is clear that people who have never studied the history of science, or have never been on the unfashionable side of a scientific debate are in for a shock upon encountering this messy and sordid reality for the first time. Not least in for a shock is the media, which has been busy identifying heartbreaking science scandals in medicine, social science, neuroscience, and economics. But curiously they offer none from the subject of climate, despite it being one of the most policy driven and lavishly funded branches of science today.

Is this because there are few examples of bad practice, irreproducibility, retraction, pal review and gatekeeping in climatology? Far from it. The Climategate emails of 2009 revealed gatekeeping at its most blatant. Who can forget Phil Jones writing to Michael Mann on 8 July 2004 ‘can’t see either of these papers being in the next IPCC report. Kevin and I will keep them out somehow – even if we have to redefine what the peer-review literature is!’ Or Steve McIntyre and Ross McKitrick struggling to publish (leading to a US Congressional hearing, no less) their comprehensive demolition of the statistical errors and data-selection issues in the infamous ‘hockey stick’ paper? Or Richard Tol’s exposure of the practices employed in the Cook et al ‘97% viii consensus’ paper? Again and again, peer-reviewed climate papers have fallen apart under post-publication scrutiny from the likes of McIntyre, Willis Eschenbach, Donna Laframboise, Judith Curry and Nic Lewis. And these do not even touch on the challenge of independently reproducing climate model output without the machinery and resources necessary to do so, as Laframboise rightly observes in the following paper.

Indeed, the field of climate science could supply a rich harvest of examples of this crisis of scientific credibility all on its own. Yet it is the scandal that dare not speak its name. The discussions of the crisis in peer review in Nature, Science, the Economist and elsewhere studiously ignore any examples from climate science. Why is this? It is an article of faith among certain scientists and science journalists that because climate scepticism is also a position supported by those on the right of politics, so nobody in science must give fodder to the sceptics.

This is nothing less than the modern manifestation of gatekeeping continuing its ancient legacy, driven by sheer ignorance and self-delusion, to keep the forces that actually advance science away from the door. Scientific research stretches human faculties to their limits, and it is at such limits where human frailties become most prominent.

Humans are fallible. That is one of the greatest lessons from the history of science. The message to be taken from these heartbreaking scientific scandals and absurdities is not one of chagrin and a temptation to adopt cynicism. The true authors of such scandals are the laymen, academics, journalists, and policymakers who do not give a fair hearing to the many highly trained scientists motivated by alternative views who would put such dubious claims to the test. A pervasive uneducated appeal to science as a monolithic incomprehensible authority, assessed only in terms of moral purity rather than factual accuracy, has made such a fair hearing nearly impossible, and done great harm to science and us all.